Effects of the interaction between shade and drought on physiological characteristics in Calamus viminalis seedlings

Recently, the endangerment of wild rattan population draws attention on the conservation and sustainable utilization of rattan resources. Rattan growing usually faces the light and water stress. Therefore, we aim to explore the combined effects of shade and drought on seedling growth, thus providing a theoretical ground for the conservation and artificial cultivation of the rattan. The combined effects of shade and drought on physiological and biochemical traits were studied in two-years-old Calamus viminalis seedlings. Photosynthetic indices including Pn, Gs, Tr, and Ci and physiological indices including MDA, SOD, POD, CAT, and Pro were measured under four levels of water treatments and four levels of shade. Shade, drought and their interaction have a significant effect on C. viminalis seedlings growth. Generally, moderate shade could alleviate the impact induced by drought. However, mild drought usually enhances the effect caused by shading. The result showed that the shade decreased Pn, Gs, and Tr but increased Ci, MDA content and Pro content. Either with the shading or drought increasing, the activity of SOD, POD, and CAT firstly increase and then declined. Drought reduced Pn, Gs, Tr, and Ci but increased the content of MDA and Pro. Overall, the result suggests that 25-50% shading and 65% RSWC water treatment are most beneficial for the growth of C. viminalis seedlings.